﻿/*******************************************************************************
 * Copyright © 2016 WaterCloud.Framework 版权所有
 * Author: WaterCloud
 * Description: WaterCloud快速开发平台
 * Website：
*********************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

namespace WaterCloud.Code
{
	public static class TreeQuery
	{
		public static List<T> TreeWhere<T>(this List<T> entityList, Predicate<T> condition, string keyValue = "F_Id", string parentId = "F_ParentId") where T : class
		{
			List<T> locateList = entityList.FindAll(condition);
			var parameter = Expression.Parameter(typeof(T), "t");
			List<T> treeList = new List<T>();
			foreach (T entity in locateList)
			{
				treeList.Add(entity);
				string pId = entity.GetType().GetProperty(parentId).GetValue(entity, null).ToString();
				while (true)
				{
					if (string.IsNullOrEmpty(pId) && pId == "0")
					{
						break;
					}
					Predicate<T> upLambda = (Expression.Equal(parameter.Property(keyValue), Expression.Constant(pId))).ToLambda<Predicate<T>>(parameter).Compile();
					T upRecord = entityList.Find(upLambda);
					if (upRecord != null)
					{
						treeList.Add(upRecord);
						pId = upRecord.GetType().GetProperty(parentId).GetValue(upRecord, null).ToString();
					}
					else
					{
						break;
					}
				}
			}
			return treeList.Distinct().ToList();
		}
	}
}